银行柜台安装了防弹玻璃以保障安全。

The bank counter is protected by ___bulletproof glass for safety.

他的计划非常周密，几乎无懈可击。

His plan was so well-designed that it was practically ___bulletproof.

他的计划看似完美，但并非无懈可击。

His plan seems perfect, but it's not completely ___bulletproof.